DE 40 39 075 describes valve gear of this type, in which a cup tappet is provided in the cylinder head for the valves that are to be operated together. The cup tappet contains a valve lash adjusting element for each of the associated valves. The valve lash adjusting elements are hydraulically connected with each other through bores and are supplied from a central hydraulic fluid chamber.
A cup tappet of this type, extending over several valves, is very expensive to produce. Ready-made parts cannot be used. Due to space limitations, it is also not practical to design a cup tappet of this type with a circular shape. Instead, it is necessary to resort to an oval form of design, which makes it more expensive to produce both the cylinder head and the valve tappet.
Another known valve of the specified type is described in DE-OS 33 44 324, in which, for the purpose of reducing the dimensions for several valves, a common, yoke-like valve tappet is proposed, which is acted upon by a restoring spring common to the valves that encloses their shafts. To guide this valve tappet, a special bolt or stud is provided in the cylinder head. Once again, this requires added production cost for both the valve tappet and the cylinder head. With a design of this type, it is not possible to use standardized cup tappets, so that the production expense of such a valve drive is greatly increased. Furthermore, the valve spring common to several valves obstructs the space that is necessary, for example, for the injection nozzle in a diesel engine with direct injection, so that this valve drive cannot be used in every type of internal combustion engine.